Issues I noticed:
When colliding with objects (like the fly and plants) it messes with the camera, possibly pull camera collision out of the objects.
Adding some menus that way exiting the game is easier, and that way there is some pausing, etc.
No way to tell which magic spell you are on, when hitting q and e there is no difference in the bottom left to tell the spells.
Maybe a score system, or more clear goals on what the endgame is.
The game is unplayable on mouse pads. Possibly remove the right click feature, or turn from a hold to a click to zoom, click to un zoom.
Clipping into objects partially.
The clipping allows you to climb objects that I don't think you meant for players to climb.
The rock ramp wasnt smooth to walk up, had to constantly jump.
If you fall between the spool and flower pot you are stuck and cannot exit.
Overall:
I liked the design, definitely interesting and all matches the game style.
I liked how the 2d items constantly kept facing the user that way they had a 3d style feel to them.
I like the implemented run in the game.
The game definitely had an aesthetic to it that is kept throughout the game.
I feel like the concept is fun, just needs more things to implement which is understandable as this is the first play test.